Brontosaurus, whose name means “Thunder Lizard,” is not an actual dinosaur. It is actually a mix of Apatosaurus, meaning “Deceptive Lizard,” and Camarasaurus, meaning “Chambered Lizard,” due to the hastiness of paleontologist Othniel Charles Marsh.
In the late 1860s, two paleontologists, Edward Drinker Cope and Marsh, became rivals and had a competition to see who could discover the most species of dinosaurs. But in their rush, they often had incomplete or inaccurate data.
In 1877, Marsh wrote a brief article that appeared in the American Journal of Science, describing Apatosaurus’s vertebral column, but he did not have any other information about the animal. In the article, he estimated that Apatosaurus was 50 feet long. Later that year, Marsh wrote another article for American Journal of Science that described a different dinosaur’s pelvis and vertebrae. He called this dinosaur Brontosaurus and he determined it to be 70 to 80 feet long.
An almost complete skeleton of Brontosaurus was put on display in Yale’s Peabody Museum, the first sauropod (large herbivore that is “lizard-footed”) to be on display anywhere. Brontosaurus became a very famous and popular dinosaur worldwide.
However, it turned out that the Apatosaurus Marsh had found earlier was not a separate species from Brontosaurus; it was actually a juvenile form of the same species. In 1903, Elmer Riggs from the Field Museum in Chicago found Marsh’s mistake. Because Marsh found and named Apatosaurus first, the rules for naming animals at the time gave the name Apatosaurus priority to Brontosaurus, and thus the dinosaur is now called Apatosaurus.
Although the mistake was known since the early 20th century, the name Brontosaurus was still used in popular culture and the media, and even on museum displays. But in 1970, scientists John McIntosh and David Berman proved that Marsh had mounted the wrong head onto Brontosaurus’s skull. Because there was no Apatosaurus head for the Brontosaurus exhibit, Marsh had purposely taken a skull from another excavation site, the skull of Camarasaurus, and mounted it onto Brontosaurus. However, the real Brontosaurus skull looks more like that of Diplodocus, another sauropod, which has a longer snout. Camarasaurus had a smaller head that was rounder with a blunt snout and spoon-shaped teeth.
In 1989, the U.S. Post Office decided to make available illustrated dinosaur stamps. But, many dinosaur enthusiasts were upset that the post office wanted to use the name Brontosaurus, since the correct name is Apatosaurus. Now, most people refer to Brontosaurus as Apatosaurus, although some people hold on to the old, technically incorrect name.
Now that you know the history behind Brontosaurus and Apatosaurus, here are five interesting facts about Apatosaurus.
Apatosaurus Fact #1: Apatosaurus lived in what is now North America during the late Jurassic Period, around 146-157 million years ago. There was a minor mass extinction towards the end of this period, during which many enormous sauropods died out, but the cause of this extinction is unknown.
Apatosaurus Fact #2: Apatosaurus was one of the biggest land dinosaurs, weighing 33-38 tons and measuring between 70-90 feet long and 15 tall at the hips. It had a head less thank two feet long, and a very small brain. Apatosaurus is considered to be one of the least intelligent dinosaurs. Apatosaurus had a long neck, with 15 vertebrae, a long tail about 50 feet long, four column-like legs, peg-like teeth, and a hollow backbone. Apatosaurus could have only held its head up to 17 feet off the ground. However, this often protected them from predators, since the largest predator at the time in North America was Allosaurus and it was only 15 feet tall. Apatosaurus’s neck may have been used to poke its head into groups of trees the Apatosaurus body would not be able to venture into.
Apatosaurus Fact #3: Apatosaurus had nostrils on the top of its head. Although it was believed that Apatosaurus lived in wetlands, it is now clear Apatosaurus lived on dry land so no one knows why the nostrils were on the top of its head. Apatosaurus was an herbivore, and it ate mostly conifers. Because Apatosaurus was so big, it probably spent all of its time eating. It used its blunt teeth to strip and gather plants, and it swallowed its food whole and used gastroliths, stomach stones, to aid in digestion.
Apatosaurus Fact #4: Apatosaurus hatched from eggs up to one foot wide. Because Apatosaurus eggs have been found in a linear pattern instead of nests, it is thought they laid eggs while walking and did not take care of the eggs. Apatosaurus may have been a solitary dinosaur that lived on average 100 years.
Apatosaurus Fact #5: Apatosaurus had large hearts and high blood pressure to pump blood through the long neck to the head and brain. Therefore, Apatosaurus probably had a blood pressure over 400 mm Mercury, which is three to four times higher than a human’s blood pressure.
Learn more about Apatosaurus in episode 161 of our podcast.
Update: Brontosaurus is back (and is a real dinosaur)
Learn more about Brontosaurus in episode 100 of our podcast.